What is allergy, Allergy causing substances, Symptomps

 

What is allergy, Allergy causing substances, Symptoms

• The hypersensitive reaction of the immune system against the foreign protein or certain antigen is called Allergy.

• The antigens or substances responsible for the allergy are called Allergens. Pollen Grains, animal dander, dust, feathers, smoke etc are common allergies. Sometimes drugs also cause allergies and produce allergic reactions in the body.

Response of body Against Allergy

• These allergic reactions appear due to release of histamine and serotonin by mast cells and basophil cells in the blood.

 Read more about the Pathogen and how do they adapt in body of host.

• During allergy, IgE antibody is produced in the body.

• There are two types of histamine receptors in the body -H1 and H2.

• The H1 receptor is present in skin, lung tissue and mucosa of intestine whereas the H2 receptor is present in gastric mucosa of the stomach.

Symptoms of Allergy

• The Allergy reaction is very quick. Its symptoms are itching dermatitis, rhinitis, watering nose, watering eyes, sneezing and sometimes respiratory affliction may occur.

• Anaphylactic shock is a condition when a patient gets severe shock from an injection of foreign protein.

• Sometimes when antigen is injected in the blood in case of bee biting, it spreads rapidly to a large number of mast cells in the body.

Read about more about the Immunity : Active & Passive immunity 

• This  results in the release of histamine in large quantities. This is an anaphylactic shock.

• The effect of anaphylactic shock is very quick. With in minutes, tissue of face swell up, the tissue around the eye become so puffy, the lips swell up etc.

• The overall inflammation of skin causes a drop down of blood pressure and victim develops a rapid Heart beat.

Drugs causing allergy

• Antihistamines drugs are given for allergy hence called anti allergic drugs. These drugs stop the circulation of histamine in blood.

• Sodium cromoglycate is another anti-allergy drug that is frequently used in respiratory allergy.

• It prevents the release of histamine from mast cells. The best prevention from allergy is to avoid the approaches of allergens.